Incus- and malleostapedotomy - Vula

OPEN ACCESS ATLAS OF OTOLARYNGOLOGY, HEAD &
NECK OPERATIVE SURGERY
INCUS- & MALLEOSTAPEDOTOMY
Tashneem Harris & Thomas Linder
Stapedotomy refers to the calibrated fenestration of a fixed footplate and insertion
of a prosthesis. Prof Ugo Fisch first introduced the terms incus-stapedotomy where
the prosthesis is attached to the long process of the incus, vs. malleostapedotomy
where the prosthesis is attached to the
malleus handle. 1 The surgical steps of
both procedures, as described by Prof
Fisch, will be described.
surgery, then a malleostapedotomy is performed. The rationale behind the endaural
approach with an enlarged tympanomeatal
flap and partial anterosuperior canalplasty
as described by Prof Fisch, is primarily to
improve surgical exposure in order to
properly assess ossicular mobility 7.
Otosclerosis is the most common indication for stapedotomy. Histology of temporal bone specimens show that there may be
a fairly high incidence (up to 30%) of
additional malleal fixation in otosclerosis.
2
Hyalinisation and ossification of the
anterior malleal ligament are related to the
duration of otosclerosis.2 Fixation of the
malleus head and incus body are usually
found in narrow external ear canals. The
reported incidence of malleal fixation in
clinical studies varies significantly for both
primary (0.6 - 6%) 3,4 and revision surgery
(3-37%).5,6 In a recent study (unpublished
data) conducted by the senior author (T.L),
the incidence was found to be 5% with
primary surgery.
Patients with otosclerosis and a conductive
hearing loss with an air-bone gap (ABG)
of >20dB are candidates for surgery.
The best way to assess mobility of the
ossicles and the anterior malleal ligament
is by visual assessment of the mobility of
the ossicles on direct palpation. This requires adequate surgical exposure; it is
difficult to assess via a limited transcanal
approach. Partial fixation may be overlooked when using a limited approach.
It is the practice of the senior author (T.L)
to use routinely the endaural approach
and to systematically expose the anterior
malleal ligament as this allows for proper
assessment and identification of impaired
ossicular mobility at the time of the
primary surgery. If there is even partial
fixity of the malleus or incus at primary
Indication for surgery
Goals of surgery
The aim of surgery is to achieve maximum
hearing gain with minimal damage to the
membranous labyrinth; it may be considered in 3 different categories depending on
the cochlear reserve of the patient:
 To achieve normal hearing in patients
with normal cochlear reserve (< 10dB
postoperative air-bone gap)
 To achieve serviceable hearing in
patients with minimal reduction in
cochlear reserve and possibly to eliminate the need for a hearing aid
 To improve hearing aid satisfaction
Note that patients with advanced otosclerosis and poor cochlear reserve who no
longer benefit from amplification are
candidates for cochlear implantation.
Preoperative evaluation
Otomicroscopy: A normal stable tympanic
membrane without retraction pockets
should be confirmed in otomicroscopy.
Tuning fork tests: Tuning fork tests are a
simple means to confirm a conductive
hearing loss, and can help confirm the
validity of the audiogram. They only
assess one single frequency (commonly
440Hz) at a time, and should be done by
the surgeon.
Tympanometry: Type A curve
Stapedial reflexes: Absent in otosclerosis
High Resolution CT (HRCT)
Audiological evaluation
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Audiometric testing should be recent
(< 3months)
Enables the surgeon to decide which
ear requires surgery 8
It includes pure tone audiometry which
typically indicates conductive hearing
loss involving the lower frequencies
with Carhart notch at 2kHz
The size of the ABG provides an indication of the gain that may be achieved
by surgery 7
A typical audiogram for otosclerosis
has a larger ABG in the low frequencies and good sound transmission at
high frequencies (4kHz). A consistent
pancochlear ABG is not typical for
otosclerosis!
A Carhart notch is characterised by the
apparent elevation of bone conduction
threshold of 15dB at 2kHz and is the
hallmark audiologic sign of otosclerosis
One can accurately determine the degree of secondary cochlear loss by
making allowance for the Carhart
notch when interpreting bone conduction thresholds; if the bone conduction
threshold is larger than 15dB at 2kHZ
it suggests underlying cochlear otosclerosis. This can help the clinician with
preoperative counselling with regard to
the anticipated outcome of surgery
In the absence of a Carhart notch it is
important to exclude other causes of
conductive hearing loss which may
mimic otosclerosis
Speech discrimination is especially
useful for determining the presence of
cochlear otosclerosis when the ABG is
>15 dB at 2kHz)
It is important to emphasize at this point
that otosclerosis is a clinical diagnosis
made on history, audiometric findings and
confirmed at surgery. However the role of
HRCT in preoperative planning and patient
counselling cannot be underplayed.
HRCT (0,5mm) is useful (but not mandatory) because it can help to confirm the
presence of otosclerosis 9; it may identify
other middle ear disorders which may
mimic otosclerosis or be coexistent; it may
confirm cochlear involvement by the
otosclerotic focus; it is useful to assess
postoperative failures and complications
e.g. sensorineural hearing loss (SNHL) or
disabling vertigo and may identify problems which need to be managed promptly
e.g. too long a prosthesis. 10
The absence of a Carhart notch suggests
another cause for the conductive hearing
loss. There have also been numerous case
reports and series of superior semicircular
canal dehiscence and other pathology
which may mimic otosclerosis and are unmasked by stapedotomy (stapedial reflex is
present in cases of dehiscence only). 11,12,
13,14
It is the practice of the senior author (T. L)
to do a HRCT scan (0,5mm-1mm) whenever patients have the following features
on pure tone audiogram:
 Conductive hearing loss but absent
Carhart notch
 Equal ABG over all frequencies
 Mixed hearing loss
 All cases of revision stapes surgery
2
The following pathologies can be excluded
with preoperative HRCT scan:
 Conductive hearing loss with an absent
stapedial reflex:
o Fixation of head of malleus to lateral tympanic wall
o Fixation of incus or erosion of incus
o Congenital ossicular deformity
o Round window atresia
o Tympanosclerosis causing obliteration of footplate
 Conductive hearing loss with an intact
stapedial reflex:
o A third window: superior or posterior semicircular canal dehiscence
o Tympanic facial nerve neuroma
blocking the stapes
o Gusher syndrome: enlarged internal
auditory meatus, enlarged endolymphatic aqueduct
o Anomalous facial nerve
CT checklist for revision surgery
 Is the prosthesis in the correct position
or is it displaced?
 In cases of vertigo, what is the depth of
insertion into the vestibule?
 Is there evidence of obliterative otosclerosis, particularly of the round
window, which may have been missed
at the primary surgery?
 Is there superior canal dehiscence or
any other 3rd third window?
 Is there additional fixation of the
malleus and/or incus?
CT scan checklist prior to performing
stapedotomy
 Can one see an otosclerotic focus
(fissula ante fenestrum)?
 Is there obliteration of the oval and
round windows?
 Is there cochlear otosclerosis? (It is
possible to have fairly extensive cochlear otosclerosis with minimally reduced hearing loss)
 Is there a risk of a CSF gusher (enlarged aqueduct, enlarged internal auditory meatus)?
 Is there semicircular canal dehiscence?
 What is the position of the tympanic
segment of the facial nerve?
 Are there any other ossicular abnormalities e.g. fixation of the malleus to
the lateral wall of the epitympanum?
 Is there a stapedial artery?
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Anaesthesia
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General or local anaesthesia may be
used
Performing the procedure under local
anaesthesia depends on the patient and
level of experience and level of comfort of the surgeon
Antibiotics are not routinely used
Antiemetics are administered intraoperatively
Surgical steps
Endaural approach (right ear)
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Infiltrate the site of the endaural skin
incision with local anaesthetic (lidocaine 1% and adrenaline diluted to
1:200 000)
Insert a nasal speculum in the external
ear canal to improve exposure
Infiltrate the skin of the external ear
canal anteriorly and posteriorly
A helicotragal incision is made using a
#15 blade (Figure 1)
It is vital to achieve adequate haemostasis at this point to avoid subsequent
troublesome bleeding
3
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Figure 1: Helicotragal incision
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Place two endaural retractors in the
entrance of the external ear canal. The
1st retractor is placed vertically; the 2nd
is placed horizontally (Figure 2)
An endaural raspatory is used to
separate the skin and soft tissue from
the bone both anteriorly and posteriorly
The meatal skin flap is elevated using a
Fisch microraspatory and an otosclerosis suction with adrenaline gauze
to separate the soft tissue from the
bone as atraumatically as possible. The
working end of the Fisch microraspatory is held at right angles to the
bone and the shoulder of the instrument
pushes the adrenaline gauze strip
towards the soft tissue. The suction
never touches the tympanomeatal flap,
but sucks on the gauze
Anterosuperior canalplasty
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The exposure may occasionally be
limited by a very prominent tympanosquamous suture which requires removal with a curette or a diamond drill
In cases where there is a very prominent anterior bony overhang which prevents adequate exposure of the anterior
tympanic spine, a limited anterior
canalplasty is performed using a 3mm
diamond burr (Figure 3).
Figure 2: Exposing the ear with two
retractors
Meatal skin flap
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Make a posterior incision in the skin of
the ear canal using a #11 blade, starting
at the annulus at 7 o’clock (5 o’clock
for left ear) and ascending upwards to
end at 12 o’clock
A 2nd incision starts anterior to the lateral process of the malleus at 3 o’clock
(right ear) and passes above the tympanosquamous suture to meet the end of
the endaural incision at 12 o’clock
It is important that the tympanomeatal
flap is made long enough anteriorly
and that the incision stays medial to the
cartilage plates
Malleus
Chorda tympani
Incus
Stapedius tendon
Canalplasty
Figure 3: Anterosuperior canalplasty
improves exposure
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It is very important that all bony work
is done before raising the tympanic part
of the tympanomeatal flap to avoid
contamination of the middle ear with
bone dust
4
membrane and rarely, congenital round
window atresia 11
Exposure of oval window
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Elevate the tympanomeatal flap towards the posterior tympanic spine in
order to elevate the annulus from the
sulcus
The pars flaccida is elevated until the
lateral process of the malleus and the
anterior malleal ligament are visible
A small curette is used to remove the
posterior tympanic spine taking care to
avoid damage to the underlying chorda tympani (Figure 4)
Figure 5: Correct handling of curette
Malleus
Incudomallear joint
Incus
VIIn
Pyramidal process
Figure 4: Small curette used to remove
posterior tympanic spine
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Remove the rim of bone obscuring the
inferior portion of the incudomallear
joint with a curette. It is important
when using the curette, to avoid subluxing the incus. The small end of the
curette is used. The index finger of the
non-dominant hand stabilises the curette anteriorly (Figure 5)
Always preserve chorda tympani. It is
mobilised but kept attached to the
tympanic membrane; this facilitates
retraction of the chorda away from the
surgical field
The final correct exposure is obtained
when the pyramidal process, the tympanic segment of the facial nerve and
the inferior incudomallear joint are all
visible (Figure 6)
Inspecting the round window is
important to exclude obliterative otosclerosis reaching the round window
Figure 6: Final correct exposure
Checking mobility of ossicular chain
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Check the mobility of the malleus and
incus with a 1.5mm, 45° hook (Figure
7)
Figure 7: Checking mobility of lateral
ossicular chain
5
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Check the mobility of the stapes
(Figure 8)
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If correctly fractured, the stapes superstructure has a long anterior and a short
posterior crus
Bleeding may occur from the mucosa
when the superstructure is removed, in
which case gelfoam with Ringer’s
lactate or diluted adrenaline solution is
placed over the footplate to achieve
haemostasis (wait 2-3 minutes)
Determining length of prosthesis
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Figure 8: Checking mobility of stapes
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If malleus and/or incus are fixed then
proceed to malleostapedotomy
If the malleus and incus are mobile and
the stapes is fixed then, using the
1.5mm, 45° hook, elevate the malleus
handle to determine where the incudostapedial joint is
Use a joint knife to separate the incudostapedial joint
Check mobility of the stapes again
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Accurate measurement of the length of
the prosthesis is crucial
A piston that is too long can contact or
even pierce the underlying membranous labyrinth
A piston that is too short will be displaced easily when the patient sneezes
or performs a Valsalva manoeuvre
A malleable measuring rod is used to
determine the distance between the
footplate and the lateral surface of the
long process of the incus (Figure 9)
Add 0,5 mm to the measured distance
to account for the protrusion of the
prosthesis into the vestibule
Removal of stapes arch
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Cut the stapes tendon with fine Bellucci scissors
Cut the posterior crus of the stapes
with (left or right) crurotomy scissors
Exposure of the pyramidal process is
essential to provide sufficient space for
the crurotomy scissors
Fracture the anterior crus at the level of
the footplate, using a 2.5mm, 45° hook
To fracture the anterior crus, insert the
2.5mm, 45° hook between the incus
and the malleus neck, close to the
footplate. The tip of the hook is close
to the level of the footplate, even if the
entire anterior crus is not visible
The hook is rotated towards the
promontory
Figure 9: Measuring rod used to
determine length of prosthesis
Trimming prosthesis
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The Storz titanium stapes piston is
placed on a special cutting block which
holds the prosthesis (Figures 10, 11)
6
Figure 10: Teflon-wire prosthesis
VIIn
Stapedotomy
Stapedius tendon
(remnant)
Round window
Figure 12: Initial small stapedotomy
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For a 0.4mm prosthesis the ideal
diameter is a stapedotomy of 0.5mm
(Figure 13)
Figure 11: Cutting block
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The trimmed prosthesis is handled with
watchmaker’s forceps and placed
upright in the 4mm hole of the cutting
block while proceeding to stapedotomy
The Storz titanium stapes piston is
hygroscopic and is therefore easier to
work with when wet. Therefore the
cutting block is moistened with a few
drops of water before placing the
piston on it
Perforating the footplate
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A set of four manual perforators are
(0.3-0.6mm) are used to make the
stapedotomy
Start with the smallest perforator
(0.3mm) and ensure that there is no
evidence of a CSF gusher before
enlarging the stapedotomy with the
larger perforators (Figure 12)
The safest place to make the stapedotomy opening is in the posterior twothirds of the stapes footplate (see
below)
Figure 13: Making the final 0.5mm
stapedotomy
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The tip of the perforator is gently
applied to the footplate without using
any force at all
The perforator is held vertically to the
stapes footplate and is gently rotated
between the thumb and index finger of
the right hand while the left hand
stabilises it (Figure 14)
The tip of the perforator only partially
enters the vestibule as the stapedotomy
opening is created by the shoulder of
the perforator
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The safest area for manipulation is
therefore the central third in the
inferior segment of the footplate
Choice of instrument for stapedotomy
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Figure 14: The perforator is gently
rotated between the thumb and index
finger of the right hand while the left
hand stabilises it
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In the senior author’s (T.L) experience,
the type of footplate is important when
selecting a perforator
An alternative to manual perforators is
a laser or a Skeeter drill. Lasers that
have been used for stapes surgery
include CO2, KTP, Argon, Diode and
Erbium:YAG lasers
When one encounters a biscuit (thick)
footplate, or a thick footplate which is
only partially fixed, then there is a risk
of causing a floating footplate
If the footplate is too thick, then it is
preferable to use a drill
Additional important points and clinical
scenarios
Footplate fracture during stapedotomy
Safest position for stapedotomy
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The risk of stapedotomy is damage to
the membranous utricle and saccule
which lie in close proximity to the
stapes footplate
Surgeons should know the safety
margins required to perform the procedure without damaging the underlying
vestibule
The minimum distances to the utricle
are at the posterior (0.58mm) and
superior (0.62mm) borders of the
footplate; therefore placing a prosthesis
to a depth of 0.5mm in this region of
the footplate will place the utricle at
risk of injury 15
The minimum distance to the saccule is
at the anterior border of the footplate
(0.76 -1mm) 14
All other measurements from the footplate to the underlying membranous
utricle and saccule are >1mm
If only small bony fragments surround
the stapedotomy opening and the opening is of the desired size, then one can
carefully elevate the fragments with a
0.2mm footplate elevator to avoid the
fragments from entering the vestibule
and causing vertigo postoperatively
(Figure 15)
Figure 15: Carefully elevate bony
fragments with 0.2mm footplate elevator
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If the footplate has been fractured but
the stapedotomy is still too small and it
is not possible to enlarge the opening
8
without displacing the bony fragments,
then the fractured segments can be
removed with either a 0.2mm footplate
elevator or a 0.5mm, 45° hook, such
that a partial or total stapedectomy is
performed. A graft is then placed over
the (partial) stapedectomy before inserting the prosthesis (Figure 16)
Inserting and crimping the prosthesis
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The prosthesis is picked up with a large
crocodile forceps from its hole in the
cutting block by its wire loop
For first-time correct placement of the
loop over the long process of the incus
it is essential to pick up the prosthesis
at the correct angle
The prosthesis is placed onto the footplate with the loop over the incus
One can estimate at this point whether
the prosthesis is too long and needs to
be shortened, or too short and needs to
be replaced
Using a 1mm, 45° hook, move the loop
of the prosthesis along the long process
of the incus so as to guide the shaft of
the piston towards the stapedotomy
opening (Figure 17)
Figure 16: Partial stapedectomy sealed
with a graft before inserting prosthesis
Floating footplate
The footplate may become completely
mobile before the stapedotomy has been
made. Management options in this
situation are:
 Proceed with the stapedotomy using a
laser
 Proceed with a total stapedectomy and
seal the oval window a graft (perichondrium / vein / fascia) before placing the piston prosthesis
 Postpone the surgery for one year if the
stapes superstructure is still intact; the
annular ligament will progressively
become refixed due to otosclerosis
Figure 17: The loop is hooked over
incus with the piston resting on the
footplate
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Once the piston is positioned within the
stapedotomy opening, the loop of the
prosthesis is crimped with a large
smooth crocodile forceps to achieve a
more stable coupling of the prosthesis
to the incus; this is repeated with
smaller smooth crocodile forceps
(Figure 18)
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Figure 18: Crimped prosthesis with
piston in stapedotomy; note position of
facial nerve immediately adjacent to
the prosthesis
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Figure 19: Crocodile forceps is held with
right hand and stabilised with left hand
using thumb and index finger
Using a 1.5mm 45° hook, check the
mobility of the ossicular chain with the
prosthesis in place
There should be no free movement of
the prosthesis on the incus when the
incus is moved
Crimping technique
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To achieve good results correct crimping is absolutely essential
Loose coupling of the prosthesis to the
incus will result in reduced sound
transmission and inferior acoustic
results 16
To crimp the loop of the prosthesis, the
crocodile forceps is held with the right
hand and stabilised with the left hand
using the thumb and the index finger
(Figure 19)
It may be necessary to remove the
horizontal retractor in order to gain
more space to crimp the prosthesis
correctly
Crimping is performed from the most
superior part loop, so that the prosthesis loop makes even contact with the
incus (Figure 20)
Figure 20: Crimping is performed from the
most superior part of the loop
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Correct angulation of the piston relative to the footplate is crucial to
achieve good acoustic results. The
piston has to be at right angles to the
footplate to avoid contact of the piston
with the bony edges of the stapedotomy which will result in attenuation
of vibration and reduced sound
transmission 17 (Figure 21)
Kwok, Fisch et al reported that crimping results depend on the instrument
used for crimping and the material of
the stapes prosthesis, but not on the
surgeon. The straight crocodile forceps
was shown in their study to produce
superior crimping results than the
McGee crimper 17
10
Repositioning tympanomeatal flap
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The tympanomeatal flap is repositioned
If any small tears in the tympanomeatal
flap are noticed, then temporalis fascia
is harvested and underlay grafting is
done
Packing and wound closure
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Figure 21: Prosthesis must be at right
angles to footplate for optimal hearing
results
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Sealing stapedotomy opening
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Connective tissue placed around the piston
serves as a seal to prevent perilymph
leakage. Once the seal has matured it also
prevents displacement of the piston. The
connective tissue seal also increases the
sound transmitting area, so that a 4mm
piston is equivalent to the surface area of a
6mm piston, therefore improving sound
transmission and achieving better acoustic
results. If one performs tympanometry at 2
weeks and no vertigo is induced, then the
seal is adequate and it is safe for patients to
fly.
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Connective tissue from the endaural
incision is used to seal the stapedotomy
opening
Use a 1.5mm, 45° hook to place pieces
of connective tissue around the
stapedotomy
Venous blood taken from the patient at
the beginning of the procedure is stored
at 3-4°C to prevent the blood from
clotting until it is needed; this blood is
now used to seal the stapedotomy
opening
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Gelfoam pledgets are placed in the
bony canal to secure the meatal part of
the flap
Do not place gelfoam pledgets over the
tympanic membrane as they could
swell and displace the prosthesis
inwards causing vertigo
Two pieces of Ivalon® are placed in
the external ear canal
The endaural incision is closed with
4/0 nylon sutures. One subcutaneous
stitch may help in readapting the
wound edges
An outer strip of gauze which has been
impregnated with antibiotic ointment
(Terracortril) is placed in the lateral
part of the external ear canal
Postoperative care
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Outer gauze dressing is removed after
one week together with the Ivalon® ear
wick
Postoperative audiograms are done at
1-2 months, 1 year and 5 years
Reversal of stapedotomy
Prof Ugo Fisch described reversing the
steps of the stapedotomy procedure in
order to reduce complications relating both
to the incus (luxations / subluxations) and
footplate (subluxations / fractures / floating
footplate). The point of departure for the
following description of the surgery is
exposure of the oval window as previously
described.
11
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Check ossicular chain mobility and
confirm stapes fixation
Determine prosthesis length and trim
the prosthesis accordingly
Stapedotomy is performed
Introduce the prosthesis and crimp it to
the incus with the stapes arch still
intact
Cut the stapedius tendon and remove
the arch of the stapes (Figure 22)
meatal flap, and exposure are identical to
that we have already described in this
chapter for incus-stapedotomy. The point
of departure of the description of the surgery that follows is exposure of ossicular
chain and oval window.
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Figure 22: Stapedius tendon and
posterior crus being cut with stapes
prosthesis already in final position and
crimped to incus
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Elevate the annulus, starting at the
posterior tympanic spine
The chorda tympani is left attached to
the tympanic membrane
The tympanic membrane is reflected
until the anterior malleal process and
ligament are exposed
Assess the mobility of the malleus
using a 1.5mm 45° hook
Use a joint knife to separate the incudostapedial joint
Mobility of the malleus and incus is
reassessed
Use a 2.5mm 45° hook to elevate
Shrapnell’s membrane from the proxymal part of the handle of the malleus
(just 1mm distal to the lateral malleal
process) (Figure 23)
Check the mobility of the ossicular
chain with the prosthesis in place
Seal the stapedotomy opening as
previously described
Malleostapedotomy
This is a technique whereby both the incus
and stapes are replaced by a single
prosthesis in order to establish a direct
connection between the malleus and the
vestibule. It is indicated for stapes fixation
with pathology of the incus and/or malleus
head that rules out an incus-stapedotomy.
Surgical exposure
The initial surgical steps relating to endaural approach, elevation of a tympano-
Figure 23: Elevating Shrapnell’s
membrane from proximal part of
handle of malleus
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The final exposure for malleostapedotomy includes the pyramidal process,
oval window niche, tympanic segment
of facial nerve, inferior part of the
incudomallear joint and anterior malleal process and ligament (Figure 24)
12
from the undersurface of the neck of
malleus with a 2.5mm, 45° hook before
drilling (Figure 26)
Malleus handle
Malleoincudal joint
Chorda tympani
Incus
VIIn
Pyramid
Figure 24: Final view of middle ear
structures before proceeding to remove
incus
Figure 26: Diamond burr being used to
excise neck and anterior process of
malleus so that malleus head may be
removed
Removal of incus and malleal head
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Laterally rotate and mobilise the incus
with a 1.5mm 45° hook, and remove it
with crocodile forceps (Figure 25)
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The malleus head is then removed
Removal of arch of stapes
Crurotomy scissors are used to cut the anterior and posterior crura close to the footplate. Note in Figure 27 that the anterior
and posterior crura are equal length; in
incus-stapedotomy the posterior crus
would be shorter than the anterior crus
Figure 25: Removing
crocodile forceps
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incus with
If the incus is bulky then the long
process of the incus is cut with a
malleus nipper so as not to injure
chorda tympani
If the ligament of the malleus is
ossified, then a 0.8mm diamond burr is
used to excise the neck and anterior
process; separate the chorda tympani
Figure 27: Anterior and posterior
crura have been cut close to footplate
Preparation of prosthesis


A 0.4mm diameter titanium piston with
a total length of 8.5mm is used
The distance between the stapes
footplate and the lateral surface of the
malleus handle (just below the lateral
13


process) is measured with a malleable
measuring rod; 0.5mm is added to this
measurement
Using the technique described for
incus-stapedotomy the desired length is
achieved by cutting the prosthesis on a
special cutting block
To confirm the correct length, the prosthesis is introduced into the middle ear
with a large crocodile forceps, so that it
extends between the malleus handle
and stapes footplate (Figure 28)
Performing the stapedotomy

A perforation is made between the
middle and inferior 1/3 of the footplate
with a manual perforator or laser as for
incus-stapedotomy (Figure 29)
Figure 29: Initial small stapedotomy
Introducing and crimping the prosthesis

Figure 28: Prosthesis placed in middle
ear to check its length




If the prosthesis extends above the
malleus handle by 0.5mm, then the
length is correct. A prosthesis that is
too long may need to be cut shorter. If
is too short then it needs to be replaced.
To accommodate the slightly off-centre
position of the malleus relative to the
stapes footplate, the shaft of the piston
has to be adapted so that it will lie
perpendicular to the stapes footplate
The loop of the prosthesis it has to be
enlarged in order to fit over the malleus
handle by stretching it open by moving
it along 1.5mm, 45° hook with a
watchmaker’s forceps
The loop may need to be adapted so
that it is oriented at 90° to the malleus
handle




Accurate crimping is crucial to obtain
good results; the larger exposure
afforded by the approach described
facilitates accurate crimping
The prosthesis is picked up by its loop
with a large alligator forceps at the
required angle and placed on the
footplate
The loop of the prosthesis is placed
over the malleus just distal to the
lateral malleal process
The loop is crimped to the malleus by
applying the alligator forceps perpendicularly to the handle of the malleus. A
McGee Crimper/Wire Closure Forceps
may be helpful to deal with the angle
between the stapedotomy and malleus
If correctly crimped, the loop of the
prosthesis should be perpendicular to
the inclination of the malleus handle
and the shaft should be perpendicular
to the stapes footplate (Figure 30)
14
3. Vincent R, Sperling NM, Oates J,
4.
5.
Figure 30: The loop is perpendicular
to malleus handle and shaft is
perpendicular to footplate
Sealing the stapedotomy
The stapedotomy opening is sealed with
connective tissue from the endaural
incision and blood taken from the patient
as described for incus stapedotomy.
Repositioning the tympanomeatal flap
and wound closure: As for incusstapedotomy
6.
7.
8.
Postoperative care



As for incus-stapedotomy
Patients are allowed to fly after 2weeks
(as for incus-stapedotomy)
Patients who have undergone malleostapedotomy are not permitted to
scuba dive
9.
References
10.
1. Fisch
U, May J. Tympanoplasty,
Mastoidectomy and Stapes Surgery.
New York: Thieme; 1994.
2. Nandapalan V, Pollak A, Langner A,
Fisch U. The anterior and superior
malleal ligaments in otosclerosis. Otol
Neurotol. 2002;23(6):854-61
11.
Jindal M. Surgical findings and longterm hearing results in 3,050
stapedotomies for primary otosclerosis:
a prospective study with the otologyneurotology database. Otol Neurotol.
2006;27(8 Suppl 2):S25-47
Vincent R, Lopez A, Sperling NM.
Malleus Ankylosis: A Clinical,
Audiometric, Histologic, and Surgical
Study of 123 Cases. Am J Otol. 1999;
20:717-25
Dalchow CV, Dünne AA, Sesterhenn
A, Teymoortash A, Werner JA.
Malleostapedotomy: The Marburg
experience. Adv Otorhinolaryngol.
2007;65:215-21
Fisch U, Acar GO, Huber AM.
Malleostapedotomy in revision surgery
for otosclerosis. Otol. Neurotol.
2001;22:776-85
Linder TE, Fisch U. A checklist for
surgical exposure in stapes surgery:
how to avoid misapprehension. Adv
Otorhinolaryngol. 2007;65:158-63
Probst R. Audiological evaluation of
patients
with
otosclerosis.
In
Otosclerosis and stapes surgery.
Arnold W, Häusler R (eds):
otosclerosis and stapes surgery. Adv
Otorhinolaryngol. Basel Karger, 2007,
vol 65, pp 119-26
Ayacha D. Lejeune D, Williams.
Imaging of postoperative complications of stapes surgery. In Otosclerosis
and Stapes Surgery. Arnold W, Häusler
R (eds): Otosclerosis and Stapes
Surgery. Adv Otorhinolaryngol. Basel
Karger, 2007, vol 65, 308-13
Linder TE, Ma F, Huber A. Round
window atresia and ist effect on sound
transmission. Otol Neurotol. 2003;
24(2):259-63
Van Rompaey V, Offeciers E, De Foer
B, Somers T. Jugular bulb diverticulum
dehiscence towards the vestibular
aqueduct in a patient with otosclerosis.
15
12.
13.
14.
15.
16.
17.
J Laryngol Otol. 2012 Mar;126(3):3135
Neyt P, Govaere F, Forton GE.
Simultaneous true stapes fixation and
bilateral bony dehiscence between the
internal carotid artery and the apex of
the cochlea: the ultimate pitfall. Otol
Neurotol. 2011.32(6):909-13
Merchant SN, Rosowski JJ, McKenna
MJ. Superior semicircular canal
dehiscence mimicking otosclerotic
hearing loss in Otosclerosis and stapes
surgery. Adv Otorhinolaryngol. Basel
Karger, 2007, vol 65, 137-45
Pauw BK, Pollak AM, Fisch U.
Utricle, saccule, and cochlear duct in
relation to stapedotomy. A histologic
human temporal bone study. Ann Otol
Rhinol Laryngol.1991;100(12):966-70
Huber AM, MA F, Felix H, Linder T.
Stapes prosthesis attachment: the effect
of crimping on sound transfer in
otosclerosis surgery. Laryngoscope.
2003;113(5):853-8
Hüttenbrink KB. Biomechanics of
stapesplasty: A review. Otol Neurotol.
2003;24:548-59
Kwok P, Fisch U, Strutz J, May J:
Stapes surgery: how precisely do
different prosthesis attach to the long
process of the incus with different
instruments and different surgeons?
Otol Neurotol 2002;23:289-95
Author
Tashneem Harris MBChB, FCORL,
MMed (Otol), Fisch Instrument
Microsurgical Fellow
ENT Specialist
Division of Otolaryngology
University of Cape Town
Cape Town, South Africa
[email protected]
Senior Author
Thomas Linder, M.D.
Professor, Chairman and Head of
Department of Otorhinolaryngology,
Head, Neck and Facial Plastic Surgery
Lucerne Canton Hospital, Switzerland
[email protected]
Editor
Johan Fagan MBChB, FCORL, MMed
Professor and Chairman
Division of Otolaryngology
University of Cape Town
Cape Town, South Africa
[email protected]
THE OPEN ACCESS ATLAS OF
OTOLARYNGOLOGY, HEAD &
NECK OPERATIVE SURGERY
www.entdev.uct.ac.za
Acknowledgements
This guide is based on the text by
Professor Fisch (Tympanoplasty, Mastoidectomy, and Stapes Surgery) and personal
experience of Professor Linder, as well as
course materials for the advanced temporal
bone course conducted annually by
Professors Fisch and Linder at the
Department of Anatomy, University of
Zurich, Switzerland
The Open Access Atlas of Otolaryngology, Head &
Neck Operative Surgery by Johan Fagan (Editor)
[email protected] is licensed under a Creative
Commons Attribution - Non-Commercial 3.0 Unported
License
16